Adjustable Chair

ABSTRACT

The adjustable chair includes a support assembly, a support arm, a sleeve seat, a telescopic post and a backrest support. The support has a tube and a plurality of positioning holes longitudinally arranged in a row. The support arm connects between the tube and a cushion and has a positioning bolt selectively inserted into one of the positioning holes. The sleeve seat is bendingly connected to the tube and has an adjusting bolt. The telescopic post is slidably accommodated in the sleeve seat and provided with adjusting holes longitudinally arranged in a row for being selectively inserted by the adjusting bolt. The backrest support is connected to the telescopic post for connecting a backrest.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates to chairs, particularly to chairs with backrest and cushion height adjustment.

2. Related Art

Chairs are a requirement in everyday life. Besides utility, chairs also must provide enough comfort to different users. A conventional adjustable chair as shown in FIG. 7 utilizes a vee support 80 for adjustably supporting a backrest 81 and cushion 82. The backrest 801 and cushion 82 are slidably mounted on an upper portion 801 and lower portion 802 of the support 80, respectively. This adjustable structure can satisfy different requirements of various users.

However, the support 80 must occupy a specific space because of its vee shape. This may cause inconvenience for small rooms. Furthermore, the support 80 is not retractable, so the top 803 will awkwardly protrude from the backrest 81 when the backrest 81 is adjusted to a lower position. A user sitting on the chair tends to be knocked on his/her head by the protrudent support 80, especially for restless children.

SUMMARY OF THE INVENTION

An object of the invention is to provide an adjustment device for chairs, which can perform height adjustment of backrest without protruding the support from the backrest. This can reduce the occupying space of the chair and is advantageous to storage and transportation. Also, the abovementioned knocking-head problem can be solved.

To accomplish the object, the adjustable chair of the invention includes a support assembly, a support arm, a sleeve seat, a telescopic post and a backrest support. The support has a tube and a plurality of positioning holes longitudinally arranged in a row. The support arm connects between the tube and a cushion and has a positioning bolt selectively inserted into one of the positioning holes. The sleeve seat is bendingly connected to the tube and has an adjusting bolt penetrating the sleeve. The telescopic post is slidably accommodated in the sleeve seat and provided with adjusting holes longitudinally arranged in a row for being selectively inserted by the adjusting bolt. The backrest support is connected to the telescopic post for connecting a backrest.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the invention;

FIG. 2 is an assembled view of the invention;

FIG. 3 is a side view showing that both the cushion and backrest are adjusted to low positions;

FIG. 4 is a back view showing that both the cushion and backrest are adjusted to low positions;

FIG. 5 is a side view showing that both the cushion and backrest are adjusted to high positions;

FIG. 6 is a back view showing that both the cushion and backrest are adjusted to high positions;

FIG. 7 shows deformation of the backrest support when being pressed; and

FIG. 8 shows a conventional adjustable chair.

DETAILED DESCRIPTION OF THE INVENTION

Please refer to FIG. 1. The chair of the invention includes a support assembly 1. The support assembly 1 has at least one tube 11. In the shown embodiment, the support assembly 1 has two parallel tubes 11 of a vee shape. These two tubes 11 are firmly sandwiched between two plates 12. One of the plates 12 is mounted with a cylinder 13. The tubes 11 are separately provided with two coaxial fixing holes 111 for being inserted by a fastener 2, which is preferably a screw. One of the tubes 11 is provided with a plurality of positioning holes 112 longitudinally arranged in a row.

A support arm 3 is connected to the support assembly 1. An end of the support 3 is formed with a tube holder 31 fastening on the support assembly 1. A positioning bolt 32 is disposed on the tube holder 31. One of the positioning holes 112 can be selectively inserted by the positioning bolt 32 for adjusting a position of the support arm 3. The support arm 3 may be further provided with one or more mounting boards 33 with connecting rods 331 for connecting a cushion 100 as shown in FIG. 2.

A sleeve seat 4 is bendingly connected to an upper end of the support assembly 1. There is a sleeve 41 accommodated in the sleeve seat 4. The sleeve 41 is located between the two tubes 11. The sleeve seat 4 is provided with an adjusting bolt 42. The sleeve 41 is bendingly connected with two connecting rods 43 with insert tongues 44. The insert tongues 44 are separately formed with threaded holes 441. The insert tongues 44 are separately inserted into the tubes 11. The sleeve seat 4 is bendingly fastened to the support assembly 1 by inserting the fasteners 2 into the threaded holes 441. The insert tongues 44 will be deformed and expanded to fasten the sleeve seat 4 onto the support assembly 1 when screwing the fasteners 2 into the threaded holes 441.

An inner sleeve 5 is accommodated in the sleeve 41. An upper end of the inner sleeve 5 is formed with a flange 51 for firmly hanging on the sleeve 41. The inside of the inner sleeve 5 is formed with two longitudinally opposite rails 52 and a through hole 53 penetrating one of the rails 52. The through hole 53 is inserted by the adjusting bolt 42.

A telescopic post 6 is slidably accommodated in the inner sleeve 5. The telescopic post 6 is formed with two longitudinally opposite troughs 61 for being separately embedded by the rails 52. One of the troughs 61 is provided with a plurality of adjusting holes 62 longitudinally arranged in a row. The adjusting bolt 42 is selectively inserted into one of the adjusting holes 62 to adjust the telescopic post 6 against the sleeve seat 4.

An end of the telescopic post 6 connects a backrest support 7 for connecting a backrest 200 as shown in FIG. 2. The backrest support 7 has two opposite ends 70, 71. These two ends 70, 71 are provided with a first connecting portion 700 for fastening to the telescopic post 6 and a second connecting portion 710 for linking the backrest 200, respectively. The first connecting portion 700 is an elastic member made of plastic. The second connecting portion 710 is a pivot for angular adjustment of the backrest 200.

Preferably, the backrest support 7 is formed with a curved portion 72 between the first and second connecting portions 700, 710 for flexibility. Please refer to FIG. 7. By means of the curved shape of the backrest support 7, the backrest 200 will be deformed toward the telescopic post 6 when it is pressed. Thus the backrest 200 can flexibly support the user's back. Preferably, the first connecting portion 700 may be further provided with a handle ring 73, which is helpful for moving the chair. A lower end of the sleeve 41 is provided with a lower sleeve 63 being penetrated by the telescopic post 6. A lower end of the telescopic post 6 is provided with a stopper ring 64 encompassing the troughs 61.

Please refer to FIGS. 3-6. The bottom of the support assembly 1 may be installed with a wheeled seat 300. The handle ring 73 may help to move the wheeled seat 300. The position of the cushion 100 connected to the support arm 3 can be adjusted by inserting the positioning bolt 32 into one of the positioning holes 112. The position of the backrest 200 can be adjusted by sliding the telescopic post 6 against the inner sleeve 5 and inserting the adjusting bolt 42 into one of the adjusting holes 62 as shown in FIG. 5. The stopper ring 64 will be blocked by the rails 52 when the telescopic post 6 is being pulled upward for preventing the telescopic post 6 from escaping out of the sleeve seat 4 as shown in FIG. 6.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. 

1. An adjustable chair comprising: a support assembly, having a tube and a plurality of positioning holes longitudinally arranged in a row; a support arm, connecting between the tube and a cushion, having a positioning bolt selectively inserted into one of the positioning holes; a sleeve seat, bendingly connected to the tube, having a sleeve and an adjusting bolt penetrating the sleeve; a telescopic post, slidably accommodated in the sleeve seat, being provided with a plurality of adjusting holes longitudinally arranged in a row for being selectively inserted by the adjusting bolt; and a backrest support, connected to the telescopic post for connecting a backrest.
 2. The adjustable chair of claim 1, wherein one end of the support assembly is sandwiched between two plates.
 3. The adjustable chair of claim 1, wherein the support assembly is provided with a fixing hole penetrated by a fastener, the sleeve seat is bendingly connected with a connecting rods with an insert tongue, the insert tongue is formed with a threaded hole, the insert tongue is inserted into the tube, and the sleeve seat is bendingly fastened to the support assembly by inserting the fastener into the threaded hole.
 4. The adjustable chair of claim 1, wherein the support arm is formed with a tube holder for fastening onto the tube, and the positioning bolt is located at the tube holder.
 5. The adjustable chair of claim 1, wherein an inner sleeve is accommodated in the sleeve, an end of the inner sleeve is formed with a flange for firmly hanging on the sleeve, an inside of the inner sleeve is formed with two longitudinally opposite rails and a through hole penetrating one of the rails, and the through hole is inserted by the adjusting bolt.
 6. The adjustable chair of claim 5, wherein the telescopic post is formed with two longitudinally opposite troughs for being separately embedded by the rails, the adjusting holes are located in one of the troughs.
 7. The adjustable chair of claim 5, wherein one end of the telescopic post is provided with a stopper ring encompassing the troughs.
 8. The adjustable chair of claim 6, wherein one end of the telescopic post is provided with a stopper ring encompassing the troughs.
 9. The adjustable chair of claim 1, wherein the backrest support has two opposite ends, the two ends are provided with a first connecting portion for fastening to the telescopic post and a second connecting portion for linking the backrest respectively.
 10. The adjustable chair of claim 9, wherein the backrest support is formed with a curved portion between the first and second connecting portions.
 11. The adjustable chair of claim 9, wherein the first connecting portion of the backrest support is provided with a handle ring.
 12. The adjustable chair of claim 9, wherein the second connecting portion is a pivot for angular adjustment of the backrest.
 13. The adjustable chair of claim 1, wherein the support assembly has two parallel tubes, and the sleeve seat is between the two tubes. 